I cannot remember where the plate you remove is on the tractor. I think it is on the right side in front of the axle near where the 3pt control shaft goes into the rear. You remove a cover plate then sandwich this plate between the cover plate and the tractor. To do so you need longer bolts. Did you get the mounting kit for the plate with the longer bolts and o-rings?
What are the markings on the ports on the edge of the plate?
If you do not know what plate to remove please take photos of the side of the tractor. You will need to remove the wheel to put the kit on (unless your a contortionist) I will then see if I can remember the plates location.